It is well known in the art of video transmission to use a terminator at the video input device to match the cable impedance thereby reducing electromagnetic interference and signal reflections to improve signal quality. Most composite video cable connections match a 75 ohm impedance cable with a 75 ohm termination resistor in the video input device.
However, a need exists to protect the circuitry of the video input device in the case where an unexpectedly high voltage is connected to the video input circuit. This protection is particularly important in automotive applications where the video input can be inadvertently connected to the automotive battery causing a large amount of power to be dissipated across the termination resistor. Typically, systems utilize a DC blocking capacitor in series with the video input. The DC blocking capacitor has the disadvantage of causing a poor low frequency response which results in either a loss of synchronization or distortions in the video signal.